When irrigating extensive areas of land, long sprinkler lines have been used for some time. Water has been supplied to these lines from buried pipes called main lines with spaced risers projecting above the surface of the ground for connection to the sprinkler lines. Each time a sprinkler line had to be disconnected from a riser to be moved to another riser, manual labor was required for this purpose. This was a laborious and time consuming operation. As time went on, the sprinkler lines, which can reach a length of a quarter of a mile and more were fitted with wheels to make them easier to move after disconnection from a riser. Eventually, power was supplied in one way or another to the wheeled lines to keep them moving slowly along the desired path parallel to the direction of the main line with flexible hoses extending between the water inlet end of the sprinkler lines and consecutive risers to which the sprinkler line was connected. Since the main line can be eight or more inches in diameter with the water pressure in the main line high, the required size and strength of the flexible hoses became extremely burdensome in manual operation. Proposals were therefore made to facilitate connection of the sprinkling lines to successive risers with the least manual effort. However, to applicant's knowledge no successful machine has been developed prior to his. Five examples of such proposals are illustrated in Engel U.S. Pat. No. 2,740,228, Stafford U.S. Pat. No. Re. 26,285, Purtell U.S. Pat. No. 3,444,941 and Smith et al. U.S. Pat. Nos. 3,381,893 and 3,446,434. The patented proposals provided complicated arrangements for connection of the sprinkler line to successive risers of the main line utilizing power assisted mechanical devices for handling a flexible hose connection (Engel and Purtell patents), a telescoping pipe (Stafford patent) and segmented swivel jointed pipes (Smith et al. patents) to achieve a nearly continuous water supply to the moving sprinkler line.
When it is considered that the connection between the main line and the sprinkler line may extend to six inches and more in diameter, the mechanical problems inherent in the patented devices will be apparent and probably constituted a barrier to the success of the patented developments in the field.
In the system of the present invention, the mechanical difficulties and complexities of the prior systems with their resulting operating and maintenance disadvantages have been eliminated by the provision of a single pivoted or rotatable connecting pipe or rigid water carrying arm effectively mounted and arranged for successive coupling with novel valves in consecutive risers on a main line by virtue of this single pipe or arm having a water outlet connected to a rotatable water receiving junction means which is carried along the length of the water main by a conveyance, the water outlet of the rotatable water receiving junction means being connected to the water inlet end of the sprinkler line through a swivel joint conduit. The conveyance carries the apparatus along and the single water carrying arm is successively connected to consecutive risers. Movement of the conveyance is halted at a midpoint between risers and power actuated means act to rotate the single water carrying arm around to position the water inlet end of the arm in registry with the succeeding riser. Means are provided at the water inlet end of the arm to make water flow connection with the succeeding risers. An important component of the present invention is a novel means for accommodating the fixed length of the water carrying arm or pipe as it rotates around each riser means while the conveyance moves along a path parallel to the main line.
The present invention incorporates features of the inventions covered by the parent patent applications but makes possible the use of an appreciably smaller and more economical conveyance, an aspect which taken with the reduction in the number of water carrying arms, greatly reduces the cost of the machine of the present invention relative to that of the earlier machines.